Graphdiyne-based metal-free catalysts: Innovations in synthesis, properties, functionalization, morphology and applications

Graphdiyne (GDY) is a novel two-dimensional carbon material characterized by unique properties, positioning it as a promising candidate for various applications in catalysis, energy storage, and electronics. This review offers a comprehensive analysis of GDY, covering its theoretical simulations, structural characteristics, and properties. This research examines the molecular structure, electronic characteristics, mechanical strength, optical behavior, and thermal and conductive properties. In addition, the potential of GDY as a metal-free catalyst, as well as its tunable pore size and surface area, are investigated. Similarly, several synthesis methods, including dry and wet chemistry, Cu-surface-mediated synthesis, and template-based strategies, are discussed, emphasizing progress in the synthesis of GDY derivatives with improved performance. The review examines various synthesis reactions, including Glaser coupling and alkynylsilane coupling, as well as methods to enhance GDY performance through bandgap engineering, doping, defect engineering, and surface functionalization. Additionally, the various dimensionalities of GDY were examined, ranging from zero-dimensional/quantum dots to three-dimensional structures, each presenting distinct advantages in applications. The functionalization of GDY with different organic and inorganic molecules, including anthraquinone and porphyrin, is examined to enhance its catalytic and electronic properties. Finally, the wide-ranging applications of GDY were explored, including its role in photocatalytic and electrocatalytic reactions for hydrogen production, oxygen evolution, overall water splitting, CO₂ reduction/conversion, as well as its use in supercapacitors, batteries, and solar cells. This review serves as a comprehensive guide for scientists interested in exploring the potential of GDY across various scientific and technological domains.